One popular GFRA protocol is irregular repetition slotted aloha (IRSA) [1]}, [2]}, which is the focus of this paper.
Users in IRSA transmit replicas of their packets on a randomly selected subset of the available REs.
The indices of the REs in which they transmit make up the access pattern matrix (APM).
Existing works in IRSA assume availability of perfect channel state information (CSI) at the BS, which is difficult to achieve, especially when non-orthogonal pilots are employed.
Channel estimation errors and pilot contamination due to non-orthogonal pilots can erase much of the gains promised by IRSA protocols.
Thus, one of the main goals of this paper is to understand the impact of estimated CSI on the performance of IRSA when non-orthogonal pilots are used.
